Concrete curb final grade machine



May 7, 1963 E. H. MORGAN CONCRETE CURB FINAL GRADE MACHINE 2 Sheets-Sheet 1 Filed Nov. 6. 1961 INVENTOR. a 1m QYW W ki/Kcflw/ ATTORNEY May 7, 1963 E. H. MORGAN CONCRETE CURB FINAL GRADE MACHINE Filed NOV. 6, 1961 2 Sheets-Sheet 2 INVENTOR. flaw-M HQh K BY 1 ATTORNEY United States Patent 3,088,231 CONCRETE CURB FINAL GRADE MACHINE Edward H. Morgan, 117 E. 51st St., Savannah, Ga. Filed Nov. 6, 1961, Ser. No. 150,563 6 Claims. (Cl. 37-108) The present invention relates to roadbuilding apparatus and more particularly it provides a new and useful concrete curb final grade machine.

In the constructionof roads and streets of poured concrete it is customary to fix steel for-ms along each side edge of the strip that is to be paved preparatory to pouring the concrete to form the curbing and gutter. These forms are elongated steel members top-flanged for rigidity and set in fixed position on the previously graded earth. They are generally spaced about twelve inches apart in accurate parallelism, with the unflanged side surfaces internally opposed and the top flanges extending oppositely outwardly. In a typical installation, one of the forms is twelve inches high and the other six inches high. It has been customary heretofore for the earth between the .two forms to be finally graded by hand labor using shovels. The object of the present invention is to mechanize this final grading operation by providing a machine that will propel itself along the forms and accurately loosen earth from between them to the desired depth, which is the plane of the bottom edges of the forms, and remove all such loosened earth, thereby leaving the space between the forms clean and fully and finally graded, ready for the concrete pouring operation.

This object is accomplished by providing a wheeled carriage, motor driven along the forms, and equipped with earth removing means comprising the combination of rotary power cutter blades and a stationary scraping assembly cooperating with the rotary cutter to insure complete removal of all the earth from between the forms by pushing forward, into engagement with the cutter, all the earth loosened by the cutter, -so that continued rotation 'of the cutter will be effective to remove all such earth by throwing it to one side, over the adjacent form.

An embodiment of the invention that has been thoroughly tested in actual service and found to be entirely satisfactory, and which is accordingly at present preferred,

is illustrated in the accompanying drawings forming part of this application for Letters Patent, in which FIGURE 1 is a side elevational view of the machine, mounted in place in operative position on a pair of curbing and gutter forms;

FIG. 2 is a top plan view of the FIG. 1 showing;

FIG. 3 is a front end elevational view of the machine; and

FIG. 4 is a transverse sectional view taken on the line 44 of FIG. 1,looking rearwardly, in the direction of the arrows.

In these drawings the reference characters A, B designate respectively'the'high and low'steel forms that have been erected inparallelism along one of the side edges of a roadway under construct-ion. In a typical operation such as has been 'selectedin this application to illustrate the invention, the form A is twelve inches high, the lower form B is six inches high, and the two are spaced twelve inches apart. Both are outwardly flanged at the top, as shown. The space between them is to be completely cleared of earth preparatory to a concrete pouring operation.

The machine provided by the invention comprises a generally oblong carriage made up of a pair of stout angle iron side members 1, 1 and cross pieces 2, 2 welded or equivalently integrated into a rigid framework having front and rear depending pedestals 3, 3 journaling sup porting and traction wheels 4, 4. These wheels are 3,88,23=l Patented May 7., 1963 flanged, and they ride on the flanged tops of the forms A, B. Because the two forms are of different heights, the wheels 4 at one side of the carriage are set higher than the wheels at the other side, in order that the top of the carriage, formed by the plane of the side members 1, 1, may constitute a horizontal bed for mounting a gasoline engine and suitable transmission mechanism as will presently be described. For this purpose each of the two pairs of pedestals 3, the pair at the front end of the machine shown at the right in FIGS. \1 and 2,'and the pair at the rear end, is provided with two vertically spaced superposed horizontal axles 5, 6, as best shown inFIGS. 1 and 3. These axles are journaled in appropriate bearings 7, 7 mounted on the inner faces of the pedestals. The lower axle 5 projects through the pedestal 3 at one side of the carriage and has its wheel 4 splined onto its protruding end, and the upper axle 6 similarly projects through the pedestal 3 at the other side of the carriage and has its Wheel 4 splined onto its protruding end. This arrangement is duplicated at each end of the carriage, as shown in FIG. 1.

In an intermediate portion of the carriage, between the front and rear sets of wheels 4, the machine is provided with a rotary cutter 8 of special form. In the illustrated embodiment of the invention this cutter has two diametrically opposed radial blades 9, 9, each spirally curved, and respectively equipped at their outer ends with replaceable sets of hardened teeth members and cutting edges 14 The rotary cutter is mounted on a shaft 11 which is journaled in bearings 12, '12 carried by the inner and outer sides of a housing 13 formed of stout steel plates depending rigidly from the frame member 1 at the side of the carriage above the lower wheel 4. The cutter 8 is thus positioned for rotation in the transverse center of the machine so that its blades span the major portion of the space between the forms A, B and the outer ends of the blades will describe a path, when the cutter is rotated, that will extend down to substantially the plane of the bottom edges of the forms. It will be apparent that when the cutter is rotated its teeth and cutting edge It will dig the earth between the forms A, B and loosen it throughout the space between the forms to substantially the depth of the forms.

To drive the rotary cutter, and at the same time propel the carriage along the forms, a gasoline engine 14 is provided. In the illustrated embodiment of the invention this is a one and one-half horsepower single cylinder four cycle engine which is mounted on a bed 15 at the forward end of the carriage, above the front wheels 4. The engine is equipped with the usual clutch and gear box 16, mounted on one of the side frame members 1 and driven by a belt 17 from the engine crankshaft and sprocketed by the chain 18 to a jackshaft 19 extending transversely of the carriage frame and journaled in bearings 29, 20 on the frame side members 1. A sprocket is splined on this jackshaft and connected by a chain 21 to the axle 6 of the forward high wheel 4, and a chain'22 is trained around sprockets of identical size fast on the axle 6 and the lower axle 5 of the forward lower wheel 4. Thus the engine drives the two forward axles 5, 6 at the same rate. It is convenient to so proportion the sprockets and their ratios as to cause the carriage to be propelled along the forms at a speed of some live feet per minute.

The engine also drives the rotary cutter 8, and this is accomplished by a chain 23 sprocketed from the jackshaft 19 to a stub shaft 24 which is journaled in the upper part of the vertical compartment or housing 13, directly above the cutter shaft 11. This shaft is connected by a chain 25 with the stub shaft. These sprockets are so proportioned that the cutter rotates at approximately rpm. when the carriage is advancing at normal speed.

The frame is extended at each of its ends by a pair of handles 26, each welded to one of the frame side members 1. These are useful in lifting the carriage into and out of operative position on the forms. One or both of the handles at the rear end of the carriage may have mounted thereon a control throttle and clutch operating handle, as conventionally depicted at 27, connected by suitable linkage, not shown, with the gas engine and its clutch mechanism.

It will be evident from the foregoing that when the engine is operating and the clutch is engaged, the carriage will be propelled along the forms in the direction of the arrow in FIG. 2, and the rotary cutter, turning in the direction of movement of the carriage, as indicated by the arrow in FIG. 1, will dig and loosen the earth between the forms to produce the desired finally graded trench. The loosened earth will be in large part thrown up by the rotating blades of the cutter and because of the spiral curvature of those blades will be discharged over the lower form B.

It has been found, however, that this action is not entirely reliable and that it is not practical to design a rotary cutter that will make accurately squared contact with the inner surfaces of the forms and dig to the flat plane which is to constitute the graded bottom of the trench.

An important object of the invention is to equip the machine thus far described with means for perfecting this earth removing function by insuring complete loosening of all the earth between the forms, down to the plane of the bottom edges of the forms, and causing all such loosened earth to be removed by the rotary cutter.

This is accomplished by the combination of a fixed scraper blade 28 of a heavy steel plate rigidly mounted behind the rotary cutter and a curved shroud device 29 similarly fixed in the framework between the blade 28 and the rotary cutter. The blade 28 spans the space between the forms, and it has a forwardly turned cutting edge along its bottom that effectively scrapes the bottom of the trench and leaves no loose earth behind it. The shroud device 29 comprises a steel plate 30 which is curved to conform to the path through which the edges of the rotary cutter blades move and is set close to that path. Behind the plate 30 is a sheet 31 of heavy leather of the kind used in transmission belting. This is riveted or otherwise securely attached to the back of the plate 30 and is proportioned to wipe with its edges the inner surfaces of the forms and the bottom of the trench.

As the carriage moves along the forms, the earth that is loosened by the rotary cutter 8 and escapes being thrown out of the trench by the rapidly turning blades is caught by the shroud and is thereby pushed forward with the advance of the carriage so that it becomes re-engaged with the blades of the cutter and is eventually thrown up and over the low form B. Such earth as may not have been cleaned from the trench by the shroud members 30, 31 will be caught and scraped from the trench bottom by the fixed blade 28 and will be by this blade pushed forward as the carriage advances. After a period of operation the space between the blade and shroud be comes packed with this scraped earth and thereafter the trench continues to be scraped clean by the blade and the earth packed before it, so that all further scrapings loosened from the trench will be pushed forward by the posed closely adjacent a portion of the path traversed solid combination of blade, packed earth and shroud and will become engaged with the cutter blades rising in front of the shroud. Thus all the earth is eifectively loosened and discharged from between the forms and the final grading of the gutter and curbing is completed by a single pass of the machine.

It is to be understood that various details of the exemplary embodiment of the invention herein described may be altered within the broad spirit of the invention as defined by the more broadly worded of the appended claims.

I claim:

1. In a concrete curb final grading machine, a carriage having supporting and traction wheels adapted to travel on elongated laterally spaced parallel steel forms, a rotary cutter journaled in the carriage and having spirally curved blades, 2. motor mounted on the carriage driving the traction wheels to propel the carriage along the forms and driving the cutter to loosen the earth between the forms and dig a trench by throwing the loosened earth up and over one of the forms, a shroud carried by the carriage behind the cutter adapted to scrape the bottom of the trench formed by the cutter and engage loosened earth escaping a cutter blade and push the same forward for discharge from the trench upon re-engagement by the cutter, and a fixed scraper blade extending transversely across the machine directly behind the shroud and having an edge at its bottom adapted to scrape the bottom of the trench.

2. The machine claimed in claim 1 in which the shroud comprises a stilf plate curved at substantially the radius of the rotary cutter and having its concave surface disposed closely adjacent a portion of the path traversed by the edges of the cutter blades.

3. The machine claimed in claim 1 in which the shroud includes a flexible leather-like sheet disposed with its side edges disposed in position for wiping engagement with the forms. 7 i

4. The machine claimed in claim 2 in combination with a flexible leather-like sheet backing the shroud plate and having its side edges disposed in position for wiping engagement with the forms.

5. The machine claimed in claim 1 in which the shroud comprises a stiff plate curved at substantially the radius of the rotary cutter and having its concave surface disby the edges of the cutter blades.

6. The machine claimed in claim 1 in which the shroud comprises the combination of a stiif plate curved at substantially the radius of the rotary cutter and having its concave surface disposed closely adjacent a portion of the path traversed by the edges of the cutter blades and a flexible leather-like sheet disposed with its side edges in position for wiping engagement with the forms.

References Cited in the file of this patent UNITED STATES PATENTS 1,684,637 Carr Nov. 8, 1927 1,918,842 Franklin July 18, 1933 1,956,931 Scullen May 1, 1934 2,837,842 Jackson June 10, 1958 

1. IN A CONCRETE CURB FINAL GRADING MACHINE, A CARRIAGE HAVING SUPPORTING AND TRACTION WHEELS ADAPTED TO TRAVEL ON ELONGATED LATERALLY SPACED PARALLEL STEEL FORMS, A ROTARY CUTTER JOURNALED IN THE CARRIAGE AND HAVING SPIRALLY CURVED BLADES, A MOTOR MOUNTED ON THE CARRIAGE DRIVING THE TRACTION WHEELS TO PROPEL THE CARRIAGE ALONG THE FORMS AND DRIVING THE CUTTER TO LOOSEN THE EARTH BETWEEN THE FORMS AND DIG A TRENCH BY THROWING THE LOOSENED EARTH UP AND OVER ONE OF THE FORMS, A SHROUD CARRIED BY THE CARRIAGE BEHIND THE CUTTER ADAPTED TO SCRAPE THE BOTTOM OF THE TRENCH FORMED BY THE CUTTER AND ENGAGE LOOSENED EARTH ESCAPING A CUTTER BLADE AND PUSH THE SAME FORWARD FOR DISCHARGE FROM THE TRENCH UPON RE-ENGAGEMENT BY THE CUTTER, AND A FIXED SCRAPER BLADE EXTENDING TRANSVERSELY ACROSS THE MACHINE DIRECTLY BEHIND THE SHROUD AND HAVING AN EDGE AT ITS BOTTOM ADAPTED TO SCRAPE THE BOTTOM OF THE TRENCH. 